Constitutional Interpretation is Voodoo

A frustrating pattern has emerged in my Constitutional Law textbook. Nearly every chapter presents a few excerpts from Supreme Court cases followed by something like this: "Why do you suppose the Court treats commercial interests differently from private citizens in this context? Consider these six possibilities put forward by legal scholars . . ."
Apparently, there are no facts about the Constitution. There are only debates. The Constitution itself, with all its amendments, occupies eighteen pages of the textbook. The rest of the book, an ostensible illumination of those eighteen pages, is another 1671 pages. It's hard to tell just what I'm supposed to be learning. On the plus side, there ought to be no wrong answers on the exam. If I write anything plausible about the Constitution, it's sure to be the position of some celebrated professor or Justice.